Item Type: Blow Off Valve Material: Aluminium OEM: SDD-BOVGRSBL, FPG250Size of Flange Pipe: Approx. 2.5in/6.4cmApplication:For TYPE-S Dump Pipe FlangeFor TYPE-RS Dump Pipe Flange When the throttle is closed rapidly, the airflow is quickly reduced, causing flow instability and pressure fluctuations.Surge can eventually lead to thrust bearing failure due to the high loads associated with it.The valve can use a combination of manifold pressure signal and spring force to detect when the throttle is closed. When the throttle is closed rapidly, the BOV vents boost in the intake tract to atmosphere to relieve the pressure and eliminate surge. 1、The BOV is a pressure relief device on the intake tract to prevent the turbo's compressor from going into surge. 2、The valve can use a combination of manifold pressure signal and spring force to detect when the throttle is closed. 3、When the throttle is closed rapidly, the BOV vents boost in the intake tract to atmosphere to relieve the pressure and eliminate surge. 4、With 8 discharge ports that draw in surrounding air and release an aggressive JDM racing discharge sound. 5、The turbo BOV has dual spring system to promote response and hold up to 30 PSI boost pressure. 6、The blow off valve is with 2 bolt mounting design and 40mm hard‑anodized valve for increased airflow.